Progress in Physics and Chemistry

Our plain-English summary of Progress in Physics and Chemistry, by V. Timbrell (1973).

The study

• Author: V. Timbrell
• Published: BIOLOGICAL EFFECTS OF ASBESTOS (J.C. WAGNER, EDITOR), LYON: IARC SCIENTIFIC PUBLICATIONS, VOLUME 8, PP. 13-16 (1973)
• Type of article: Conference paper
• Our copy: from Johns-Manville's own medical library. The article is still under copyright, so we describe it here rather than post it.

In plain English

This is a progress report by the author on work recommended by a 1964 UICC Working Group. It covers standard asbestos reference samples for research and methods for finding asbestos in tissue. The samples were prepared in Johannesburg in 1966 from donated commercial anthophyllite, amosite, crocidolite and Rhodesian chrysotile, plus a Canadian sample whose fibre name is cut off in the scan. Each finished sample (1000 lbs) contained about 70% respirable particles. The samples were analysed by many chemical and physical methods. Distribution centres recorded 250 recipients, with 30 requests in the last six months, and over 100 published articles described the samples. The author reported that no satisfactory method for measuring asbestos in tissue residues had been reported. The author described a preliminary method in which amphibole fibres line up in magnetic fields. For lungs of rats exposed by inhalation to a single amphibole type, whose residues were virtually free of interfering substances, the author expected this method to make it possible to assess 1 microgram of fibre. The author stressed that its use on human tissue still needed confirmation and would be harder, especially after exposure to more than one asbestos type.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Progress report (review) on preparing and characterising the UICC standard reference samples of asbestos and on methods for identifying and measuring asbestos in tissue; not a study of people or animals
• Who was studied: No human or animal study population. The subject was reference samples of commercial asbestos prepared in Johannesburg in 1966. The Canadian sample came from fibre from eight mines; the other samples each came from a single mine.
• Exposure: Commercial fibres of anthophyllite (origin cut off in the scan), amosite (Transvaal), crocidolite (North-Western Cape Province), chrysotile (Rhodesia), and a sample from Canada whose fibre name is cut off in the scan
• Main results:
  • The raw material came in 150 bags. Of this, 20% went to pilot experiments, 40% to preparing the samples, and 40% was set aside for possible future use.
  • The reference samples (1000 lbs of each) contained roughly equal proportions, about 70%, of respirable particles, measured with Hexhlet-type instruments
  • The two distribution centres (Johannesburg and Penarth) recorded 250 recipients
  • There were 30 requests for samples in the last six months
  • Information on the samples' characteristics and biological effects had appeared in over 100 published articles
  • The author cited earlier intrapleural inoculation experiments by Wagner & Berry (1969) as showing that oil-extracted asbestos had carcinogenicity similar to untreated fibre. For that reason, waxes and oil from asbestos were not prepared for distribution.
  • No satisfactory method had been reported for measuring asbestos quantitatively in residues left after digesting tissue
  • In a preliminary magnetic-field method, amosite and crocidolite fibres in liquid suspension lined up differently from each other. The author expected that, in lungs of rats exposed by inhalation to single types of amphibole, whose residues are virtually free of interfering substances, measuring the scattered light should make it possible to assess 1 microgram of fibre.
• The authors' conclusion: The author reported that the standard samples, and the idea behind them, had been well received and widely used. The author also reported that methods for measuring asbestos in tissue still needed development.
• Limitations the authors state:
  • The author stressed that the magnetic-field method still needed confirmation that it works generally on human tissue
  • The author stated that examining human tissue by this method is more difficult, especially when the tissue was exposed to more than one type of asbestos

Topics

Medical terms in this study, explained in our Lexicon: UICC, Anthophyllite, Amosite, Crocidolite, Chrysotile, Amphibole Group.

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